The power system for an internal-combustion multiple unit train includes a diesel generator set, a charging set, an air and hydraulic oil cooling apparatus for diesel engine, an inlet air filter etc, which are integrated together and mounted on a common frame to form a power system module, and the power system module is mounted in a suspended manner below the chassis of the carriage body, so as to save space for passenger compartments.
Since it is necessary to frequently detect, maintain and replace parts of the power system, an access opening is provided on floorboard of a passenger compartment and chassis of the carriage body, to facilitate to overhaul the power system suspended under the chassis, and the access opening is covered by an access door, ensuring that a normal function of the passenger compartment for carrying passengers during operation would be affected.
In a carriage body of a railway vehicle in the prior art, the access door is generally a piece of plywood with a shape matched with the access opening, the upper surface of the plywood is fixedly covered with a floorboard cloth layer, and is also fixedly arranged with a handle, to facilitate to lift the access door and open the access opening. However, such an access door in form of a single-layer plywood has a poor structural strength, and is easily deformed, or even fractured when the passenger compartments are overloaded, and thus affecting the driving safety; besides, the sealing and sound-proofing properties are also poor, so that most of the noises caused during operating of the devices in the power system are transferred to the passenger compartments, and thus the passenger compartments become relatively noisy.